Interesting. And concerning. I'm now experiencing the exact same issue, primarily where I work , ZIP Code 97208 (NW Portland, OR), between 8:00 AM - 6:00 PM. Like you, I have the HTC One (M8) and the issue started approximately 3-4 weeks ago. Yesterday's OOKLA's speed test was an abysmal 0.53 Mbps down / 0.06 Mbps up / Ping = 94 ms. Progress, I guess, considering it didn't time out. And yes, those are 4G LTE (XLTE???) numbers with an acceptable signal strength of -97 dBm. Previous "down" numbers in my office were in the 7-10 Mbps range = fast load times of web pages; fast downloads of apps from Google Play Store; no stuttering / buffering of streaming audio/video and so on...
By the way, in my case, I highly doubt it's a device issue. My co-worker, who sits three feet to my right, has the same issue. She's also on VZW, using a new LG Vista. We're paying premium rates for a premium Network, and frankly, this is unacceptable.
**Note** For what it's worth I believe I stumbled upon a work-around late yesterday afternoon: I changed my Preferred Network to CDMA mode(3G). While in CDMA mode both TuneIn and iHeart Radio streamed flawlessly. Absolutely zero stuttering, buffering and freezing. Web pages loaded and apps (IMDB) started working again, albeit slowly. It's a small sample size and I'll continue to test; however, 3G should not work better than LTE, nor I should I have to toggle back and fourth between 3G/LTE. This screams of tower issues, or worse, network saturation and congestion.
